The OLED (Organic Light-emitting Diode) display panel may include a top emission type OLED display panel and a bottom emission type OLED display panel, and the light of the top emission type OLED display panel is emitted from a side of the cathode. In order to ensure the transmittance of light, it is necessary to reduce the thickness of the cathode, however, a resistance of the cathode increases as the thickness of the cathode decreases. Therefore, an auxiliary cathode may be disposed on the cover plate in the top emission type OLED display panel to reduce the resistance of the cathode, thereby improving the display quality of the top emission type OLED display panel. At the same time, in order to further improve the display quality of the OLED display panel, an optical sensor is disposed on the cover plate in the OLED display panel, by which the brightness of each pixel in the display panel is detected, and the pixel is optically compensated when the brightness of light emitting of the pixel is low.
However, when the auxiliary cathode and the optical sensor are simultaneously disposed on the cover plate in the top emission type OLED display panel, the entire fabricating process is complicated with a high cost, and the occupied space of the cover plate in the display panel is increased.